The invention relates to a method and apparatus for applying dyes to the interior surfaces of passageways, such as the passages of air conditioning components.
Fluorescent dyes may be used in conjunction with ultraviolet or near ultraviolet lamps to detect refrigerant leaks in air conditioning and refrigeration systems. Typically, when a leak is suspected, dye is injected into the air conditioning system using an injector and a refrigerant charging station to force the dye into the system. Alternatively, dye may be injected using hydraulic devices, such as caulking guns or screw cartridge devices. These devices are used to overcome the internal pressure in the system to force the dye into the air conditioning closed loop unit. Once the dye has been injected into the air conditioning system, it mixes with the refrigerant and lubricating oil of the air conditioner. As the dye dissolves and circulates, it reaches the leak site and escapes from the system with the refrigerant and lubricating oil. An ultraviolet or near ultraviolet lamp may then be used to illuminate the air conditioning system. When ultraviolet light contacts the escaped dye, the dye fluoresces to indicate the location of a leak.
In the manufacturing or assembly of an air conditioning system, it is not desirable in the production line process to use the traditional methods described above to inject dye into the air conditioning system. It often takes considerable time for the dye to be distributed throughout the air conditioning system before it is forced out of the system at the leak site. The above methods may also lead to imperfect distribution of the dye within the air conditioning system because the dye is typically introduced to the system at a limited number of access points. Furthermore, spilling and leakage of the dye during injection of the dye into the air conditioning unit may cause false or inaccurate leak indications when the system is later illuminated to search for leaks.
There are known methods of placing fluorescent dye into an air conditioning system during manufacturing or assembly of the air conditioning system. These methods include placing a dye laden substrate, such as felt or a tablet, into a dehydrator or accumulator of the system before assembly. Once the system is assembled, it is evacuated to remove air and moisture, and then charged with refrigerant and lubricant. The dye dissolves in the refrigerant and system lubricant, and when a leak forms, seeps from the system at a leak site. Using this method, the diffusion of dye through the air conditioning system may be inadequate, making leaks more difficult to detect. If a solid dye is used, the dye might not completely dissolve. As a result, the undissolved dye particles might interfere with the operation of the air conditioning unit. In particular, the compressor of the air conditioner may be negatively affected if these undissolved dye particles are introduced into the compressor mechanism. Furthermore, the substrate remains in the system after the dye dissolves, and the continued presence of the substrate may negatively affect the flow of refrigerant through the air conditioning system.
While there are known methods for placing leak indicators in air conditioning systems, it would be advantageous to supply a leak indicator with individual components of the system before assembly in to a larger system. The leak indicator may be in the form of a thin film or coating applied to a portion, or to the entirety of, an internal surface of a component or components.
Based on the foregoing, alternative methods of applying dye to air conditioning components are desirable.
The invention consists of a method of applying dye to an interior surface of a component of an air conditioning unit, prior to assembly of said component in an air conditioning system. According to one broad aspect of the invention, the method comprises the steps of:
a) placing a selected amount of dye into a measuring device; and
b) dispensing said dye into an opening of said component to coat an interior, surface of said component.
According to another broad aspect of the invention, there is provided a method of applying dye to an interior surface of a component of an air conditioning unit, the method comprising the steps of:
a) placing a selected amount of dye into a measuring device; and
b) dripping said dye into the component to coat at least part of the interior surface of the component.
According to another broad aspect of the invention, there is provided a method of detecting leaks in an air conditioning unit, the method comprising the steps of:
a) placing a selected amount of dye into a measuring device;
b) dispensing the dye into an opening of the component to coat an interior surface of the component;
c) installing the component in the air conditioning unit;
d) injecting refrigerant and lubricant into the air conditioning unit to dissolve the dye;
e) illuminating the air conditioning unit with ultraviolet light; and
f) checking said illuminated air conditioning unit for fluorescing dye, which indicates the location of a leak.
According to yet another broad aspect of the invention, there is provided a method of detecting leaks in an air conditioning unit, the method comprising the steps of:
a) applying an amount of dye to a screen;
b) installing the screen in a conduit of the air conditioning unit;
c) injecting refrigerant and lubricant into the air conditioning unit and dissolving dye in the lubricant;
d) illuminating the air conditioning unit with ultraviolet light; and
e) checking the illuminated air conditioning unit for fluorescing dye.
According to yet another broad aspect of the invention, there is provided a method for applying a leak detection dye to an interior surface of an air conditioning component and to introduce said dye into an air conditioning system, the method comprising the steps of:
a) placing a selected amount of dye into a measuring device;
b) dispensing said dye into an opening of said component to coat an interior surface of said component;
c) installing said component into said air conditioning unit;
d) injecting refrigerant and lubricant into said air conditioning unit to dissolve said dye; and
e) circulating said refrigerant and lubricant.
According to another broad aspect of the invention, there is provided a method of applying an internal coating to a fluid conduit component before assembly of that component in a fluid circuit, the method comprising the steps of:
a) placing a selected amount of coating material into a measuring device; and
b) dispensing said coating material into an opening of said component to coat an interior surface of said component.
According to another broad aspect of the invention, there is provided an apparatus for applying dye to an interior surface of a component of an air conditioning unit, prior to assembly of said component in an air conditioning system, said apparatus having a means for placing a selected amount of dye into a measuring device; and a means for dispensing said dye into an opening of said component to coat an interior surface of said component.